"A test of the hypothesis that an inverted-U relationship exists between the level of arousal and performance level was made by comparing the performance of 31 Ss on an auditory tracking task under different conditions of incentive . . . the data of this study give strong support to the hypothesis. The hypothesis held regardless of whether palmar conductance level or the EMG response of any one of four different muscle groups was used as the criterion of arousal." (PsycINFO Database Record (c) 2006 APA, all rights reserved)